The invention relates to the field of heat exchangers and deals more specifically with a manifold for a header tank, of the type comprising a substantially flat plate with openings to accept tubes of a heat exchanger, and turned-up lateral edges extending at an angle to said plate and connected thereto by at least one curved portion in which ribs are formed, the ribs each having a convexity extending substantially in the direction of extension of the lateral edges.
Manifolds such as this are used in particular in header tanks obtained by two-part manifold assembly, namely a manifold and a cover, the manifold usually being made of aluminum or aluminum-based alloy.
Header tanks such as this are used in heat exchangers and, in particular, in motor vehicle engine cooling radiators or radiators used as intercoolers. In such radiators, the coolant or the supercharging air flowing through the header tank and through the tubes is at a high pressure and at a temperature that may exceed 100° C. One of the chief difficulties when designing such header tanks is that of making the manifold suitably able to withstand pressure without using too great a thickness of material from which to make it.
Certain header tanks the design of which is aimed at solving this problem are already known, for example the one disclosed in US 2003 217838. In that document, the manifold has a substantially U-shaped cross section and its thickness is doubled by a fold of material where the branches of the U meet the bottom of this U. This type of design increases the amount of raw material used and occupies a great deal of space, and the fact that the manifold has to be brazed to itself at the folds prevents, among other things, the use of a corrosion-resistant coating within it.
FR 2 720 490 discloses a manifold plate that has openings in a substantially flat region that meets at least one curved region of cylindrical overall shape deviating from the plane of the flat region, in which the cylindrical shape is interrupted by a multitude of recessed zones. While it offers good yield strength, this type of manifold plate is nonetheless particularly ill-suited to the insertion of tubes.
The invention aims to improve the situation.